Abstract: A polycrystal diamond fluted tool is provided which is capable of effecting working with much higher accuracy and longer life as compared with the sintered diamond straight fluted tool of the prior art, and is particularly suitable for finishing working with high accuracy. The tool is produced by forming, by a vapor phase synthesis method, a polycrystal diamond film on the surface of a substrate which has been subjected to helical grinding, then subjecting the product to a chemical treatment to dissolve and remove only the substrate, brazing the resulting polycrystal diamond film in a fluted form to at least a part of the rake face of a tool base metal which has been subjected to helical grinding in a similar manner to the substrate, and then subjecting the brazed tool base metal to working of a flank face to form a cutting edge.

Abstract: A composite tool with a higher bonding strength and higher heat resistance is provided comprising an insert of a hard material such as composite diamond or BN compacts and a support of a hard metal or alloy such as steel and cemented carbides, having a larger volume than the insert, the insert and support being bonded by friction welding through an interlayer of a high strength metal or alloy such as Co and Ni with a thickness of at most 1 mm.

Abstract: A sintered compact is obtained by sintering a mixture containing about 50 to 75 percent by volume of cubic boron nitride and about 25 to 50 percent of a binder under cBN-stable superhigh pressure conditions. The binder contains about 20 to 50 percent by weight of Al and one or more Ti compounds selected from the group consisting of TiN.sub.z, Ti(C,N).sub.z, TiC.sub.2, (Ti,M)C.sub.z, (Ti,M) (C,N).sub.z and (Ti,M)N.sub.z, wherein M indicates a transition metal of the group IVa, Va or VIa of the periodic table excepting Ti, and wherein z is within a range of 0.5.ltoreq.z.ltoreq.0.85. The atomic ratio of the content of Ti to that of the transition metal M in the binder is within the range of about2/1.ltoreq.Ti/M.ltoreq.97/3.The binder further contains tungsten or one or more tungsten compounds, whereby the total tungsten concentration in the binder is about 4 to 40 percent by weight.

Abstract: A composite tool with a higher bonding strength and higher heat resistance is provided comprising an insert of a hard material such as composite diamond or BN compacts and a support of a hard metal or alloy such as steel and cemented carbides, having a larger volume than the insert, the insert and support being bonded by friction welding through an interlayer of a high strength metal or alloy such as Co and Ni with a thickness of at most 1 mm.

Abstract: Herein is disclosed a high hardness sintered diamond compact and a process for the production of the same.The high hardness sintered diamond compact comprises 80 to 95% by volume of diamond particles, 0.5 to 5% by volume of a carbide particles selected from a group consisting of WC and (Mo,W)C and having a diameter not larger than 1 micron, and 4.5 to 15% by volume of an iron group metal, at least 95% by volume of said diamond particles having a diameter from 0.1 to 2 micron and the remainder of the diamond particles being particles having a diameter smaller than 0.1 micron.The ratio by volume of the amount of the diamond particles having a diameter from 1 to 2 micron to that of the diamond particles having a diameter from 0.1 to 1 micron ranges from 4 to 1.The high hardness sintered diamond compact according to the present invention is preferably usable as a drawing die for drawing a high hardness plated-steel wire and as a tool bit.

Abstract: A cBN sintered compact for an end mill obtained by sintering mixed powder prepared by mixing about 35 to 50 percent by volume of cubic boron nitride powder smaller than about 2 .mu.m in average particle size with about 50 to 65 percent by volume of a binder under cBN-stable superhigh pressure conditions. The binder contains about 20 to 30 percent by weight of Al and one or more Ti compounds selected from a group of TiN.sub.z, Ti(C,N).sub.z, TiC.sub.z, (Ti,M)C.sub.z, (Ti,M) (C,N).sub.z and (Ti,M)N.sub.z (where M indicates a transition metal element of the group IVa, Va or VIa of the periodic table excepting Ti and z is within a range of about 0.7.ltoreq.z.ltoreq. about 0.

Abstract: A diamond sintered body for tools contains a diamond content in excess of 93 percent and not more than 99 percent by volume and a residue including at least one of a metal or a carbide selected from groups IVa, Va and VIa of the periodic table and an iron group metal of 0.1 to 3 percent by volume in total and pores at least 0.5 percent and not more than 7 percent by volume.

Abstract: An improved diamond compact of the present invention comprises 20 to 85% by volume of diamond grains with a grain size of at least 3 .mu.m and the balance of a binder consisting of 20 to 95% by volume of ultra-fine diamond grains with a grain size of at most 1 .mu.m, at least one member with a grain size of at most 1 .mu.m, selected from the group consisting of carbides, carbonitrides, nitrides, borides of Group 4a, 5a and 6a elements of Periodic Table, solid solutions thereof and mixed crystals thereof and at least one member selected from the group consisting of iron group metals.

Abstract: The invention enables to obtain a compound sintered compact for use in a cutting tool having particularly high properties in respect of bonded strength, hardness, wear resistance, plastic deformability and rigidity by bonding a diamond or cubic boron nitride containing hard layer to a cemented carbide substrate with interposition of an intermediate bonding layer.

Abstract: The invention relates to a sintered compact for use in an ultrahard tool having high resistance to heat and wear, outstanding thermal conductivity and thermal shock resistance property at elevated temperature, and suitable for high-speed cutting, and to a method for producing the same. A powder mixture comprising 20-80 volume % high pressure form boron nitride powder, the residual part consisting of Al.sub.2 O.sub.3 powder or a compound ceramic powder principally comprising Al.sub.2 O.sub.3 powder and also containing carbides, nitrides of IVb, Vb, VIb metals of the periodic table, mutual solid solution thereof or admixture thereof, is sintered as it stands or after pressing under a high pressure and a high temperature so that Al.sub.2 O.sub.3 of the compound ceramic constitutes a continuous phase in the structure of the sintered compact, and the half width of (116) in the X-ray diffraction of CuK.alpha. ray of Al.sub.2 O.sub.